1. Technical Field
The invention relates to vehicle primary frames and subframes, and in particular to frames and subframes of heavy-duty vehicles, including articulated vehicles such as tractor-trailers or semi-trailers, straight trucks, and dump trucks. More particularly, the present invention relates to the utilization of a compressed air tank, commonly found on such vehicles for supplying air to various pneumatically-operated vehicle components, as a structural member of the frame or subframe.
2. Background Art
It is well known in the heavy-duty vehicle art that articulated vehicles such as tractor-trailers, straight trucks, dump trucks, and the like, typically employ suspension assemblies of various types which are located between the wheel axles and the vehicle frame or subframe. These suspensions serve to support the vehicle and its load upon the wheel axles and tires and provide a smooth ride, despite uneven road conditions and the like, to cargo and/or passengers being carried by the vehicle.
Suspension assemblies may be either directly interposed between the vehicle frame and the wheel axle assemblies, or between the wheel axle assemblies and a subframe that typically is movably mounted on the primary vehicle frame of certain types of tractor-trailers and which is commonly referred to as a “slider”. One such prior art slider application which could incorporate the instant invention is shown in U.S. Pat. No. 5,642,896, which is hereby fully incorporated by reference herein.
It is understood that both vehicle primary frames and secondary frames or subframes typically utilize a pair of spaced-apart, parallel, elongated and longitudinally-extending main members, and a plurality of transversely-extending, spaced-apart and parallel cross members which are perpendicular to the main members and are secured thereto to form an integral rigid frame or subframe structure.
It is also well known that heavy-duty vehicles of the type set forth hereinabove typically include pneumatically-operated devices or systems, including air brakes and air suspensions, as well as various other pneumatic components that might be used depending on the particular vehicle type and/or application. A pressurized or compressed air reservoir or tank is, accordingly, required equipment on such vehicles to enable air to be supplied to such pneumatic devices, systems or components for proper operation. Generally, such air tanks either are bolted to the frame or subframe cross members or longitudinal members in many possible configurations, with or without adapting brackets, and are not a structural component of the frame or subframe. However, such an arrangement adds weight to the vehicle and takes up valuable space within the frame or subframe itself, with both consequences generally being undesirable.
Instead, it is generally desirable to reduce the weight of such heavy-duty vehicles and simplify their construction as much as possible. The present invention solves such problems by enabling the air tank to double as a structural member of the vehicle frame or subframe, by replacing one or more cross members with one or more tanks to achieve weight reduction and structural simplicity, and at the same time maintain or increase the structural integrity of the frame or subframe.